[PATCH net-next v2 4/7] devlink: allow subports on devlink PCI ports

[Jakub Kicinski <jakub.kicinski@netronome.com>]

PCI endpoint corresponds to a PCI device, but such device
can have one more more logical device ports associated with it.
We need a way to distinguish those. Add a PCI subport in the
dumps and print the info in phys_port_name appropriately.

This is not equivalent to port splitting, there is no split
group. It's just a way of representing multiple netdevs on
a single PCI function.

Note that the quality of being multiport pertains only to
the PCI function itself. A PF having multiple netdevs does
not mean that its VFs will also have multiple, or that VFs
are associated with any particular port of a multiport VF.

Example (bus 05 device has subports, bus 82 has only one port per
function):

$ devlink port
pci/0000:05:00.0/0: type eth netdev enp5s0np0 flavour physical
pci/0000:05:00.0/10000: type eth netdev enp5s0npf0s0 flavour pci_pf pf 0 subport 0
pci/0000:05:00.0/4: type eth netdev enp5s0np1 flavour physical
pci/0000:05:00.0/11000: type eth netdev enp5s0npf0s1 flavour pci_pf pf 0 subport 1
pci/0000:82:00.0/0: type eth netdev p4p1 flavour physical
pci/0000:82:00.0/10000: type eth netdev eth0 flavour pci_pf pf 0

$ devlink -jp port
{
    "port": {
        "pci/0000:05:00.0/0": {
            "type": "eth",
            "netdev": "enp5s0np0",
            "flavour": "physical"
        },
        "pci/0000:05:00.0/10000": {
            "type": "eth",
            "netdev": "enp5s0npf0s0",
            "flavour": "pci_pf",
            "pf": 0,
            "subport": 0
        },
        "pci/0000:05:00.0/4": {
            "type": "eth",
            "netdev": "enp5s0np1",
            "flavour": "physical"
        },
        "pci/0000:05:00.0/11000": {
            "type": "eth",
            "netdev": "enp5s0npf0s1",
            "flavour": "pci_pf",
            "pf": 0,
            "subport": 1
        },
        "pci/0000:82:00.0/0": {
            "type": "eth",
            "netdev": "p4p1",
            "flavour": "physical"
        },
        "pci/0000:82:00.0/10000": {
            "type": "eth",
            "netdev": "eth0",
            "flavour": "pci_pf",
            "pf": 0
        }
    }
}

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
---
 .../net/ethernet/netronome/nfp/nfp_devlink.c  |  6 ++--
 include/net/devlink.h                         | 13 ++++---
 include/uapi/linux/devlink.h                  |  1 +
 net/core/devlink.c                            | 36 ++++++++++++++++---
 4 files changed, 45 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
index bf7fd9614152..6ad2805f1efc 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_devlink.c
@@ -378,12 +378,14 @@ int nfp_devlink_port_init(struct nfp_app *app, struct nfp_port *port)
 		return nfp_devlink_port_init_phys(devlink, port);
 	case NFP_PORT_PF_PORT:
 		devlink_port_type_eth_set(&port->dl_port, port->netdev);
-		devlink_port_attrs_pci_pf_set(&port->dl_port, port->pf_id);
+		devlink_port_attrs_pci_pf_set(&port->dl_port, port->pf_id,
+					      port->pf_split,
+					      port->pf_split_id);
 		return 0;
 	case NFP_PORT_VF_PORT:
 		devlink_port_type_eth_set(&port->dl_port, port->netdev);
 		devlink_port_attrs_pci_vf_set(&port->dl_port, port->pf_id,
-					      port->vf_id);
+					      port->vf_id, false, 0);
 		return 0;
 	default:
 		return -EINVAL;
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 00ceff76762c..6a29ce80cb38 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -53,6 +53,8 @@ struct devlink_port_attrs {
 		struct {
 			u32 pf_number;
 			u32 vf_number;
+			bool multiport;
+			u32 subport_number;
 		} pci;
 	};
 };
@@ -579,9 +581,11 @@ void devlink_port_attrs_set(struct devlink_port *devlink_port,
 			    u32 port_number, bool split,
 			    u32 split_subport_number);
 void devlink_port_attrs_pci_pf_set(struct devlink_port *devlink_port,
-				   u32 pf_number);
+				   u32 pf_number, bool multiport,
+				   u32 subport_number);
 void devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port,
-				   u32 pf_number, u32 vf_number);
+				   u32 pf_number, u32 vf_number, bool multiport,
+				   u32 subport_number);
 int devlink_port_get_phys_port_name(struct devlink_port *devlink_port,
 				    char *name, size_t len);
 int devlink_sb_register(struct devlink *devlink, unsigned int sb_index,
@@ -798,13 +802,14 @@ static inline void devlink_port_attrs_set(struct devlink_port *devlink_port,
 
 static inline void
 devlink_port_attrs_pci_pf_set(struct devlink_port *devlink_port,
-			      u32 pf_number)
+			      u32 pf_number, bool multiport, u32 subport_number)
 {
 }
 
 static inline void
 devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port,
-			      u32 pf_number, u32 vf_number)
+			      u32 pf_number, u32 vf_number, bool multiport,
+			      u32 subport_number)
 {
 }
 
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 9ce76d4f640d..417ae8233cce 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -336,6 +336,7 @@ enum devlink_attr {
 
 	DEVLINK_ATTR_PORT_PCI_PF_NUMBER,	/* u32 */
 	DEVLINK_ATTR_PORT_PCI_VF_NUMBER,	/* u32 */
+	DEVLINK_ATTR_PORT_PCI_SUBPORT,		/* u32 */
 
 	/* add new attributes above here, update the policy in devlink.c */
 
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 49216b688c5b..a7dd958be513 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -541,6 +541,11 @@ static int devlink_nl_port_attrs_put(struct sk_buff *msg,
 		if (nla_put_u32(msg, DEVLINK_ATTR_PORT_PCI_PF_NUMBER,
 				attrs->pci.pf_number))
 			return -EMSGSIZE;
+
+		if (attrs->pci.multiport &&
+		    nla_put_u32(msg, DEVLINK_ATTR_PORT_PCI_SUBPORT,
+				attrs->pci.subport_number))
+			return -EMSGSIZE;
 		return 0;
 	default:
 		return -EINVAL;
@@ -5449,15 +5454,20 @@ EXPORT_SYMBOL_GPL(devlink_port_attrs_set);
  *	@devlink_port: devlink port
  *	@pf_number: PCI PF number, in multi-host mapping to hosts depends
  *	            on the platform
+ *	@multiport: PCI function has more than one logical port
+ *	@subport_number: PCI function has more than one logical port
  */
 void devlink_port_attrs_pci_pf_set(struct devlink_port *devlink_port,
-				   u32 pf_number)
+				   u32 pf_number, bool multiport,
+				   u32 subport_number)
 {
 	struct devlink_port_attrs *attrs = &devlink_port->attrs;
 
 	attrs->set = true;
 	attrs->flavour = DEVLINK_PORT_FLAVOUR_PCI_PF;
 	attrs->pci.pf_number = pf_number;
+	attrs->pci.multiport = multiport;
+	attrs->pci.subport_number = subport_number;
 	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
 }
 EXPORT_SYMBOL_GPL(devlink_port_attrs_pci_pf_set);
@@ -5469,9 +5479,12 @@ EXPORT_SYMBOL_GPL(devlink_port_attrs_pci_pf_set);
  *	@pf_number: PCI PF number, in multi-host mapping to hosts depends
  *	            on the platform
  *	@vf_number: PCI VF number within given PF (ignored for PF itself)
+ *	@multiport: PCI function has more than one logical port
+ *	@subport_number: PCI function has more than one logical port
  */
 void devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port,
-				   u32 pf_number, u32 vf_number)
+				   u32 pf_number, u32 vf_number, bool multiport,
+				   u32 subport_number)
 {
 	struct devlink_port_attrs *attrs = &devlink_port->attrs;
 
@@ -5479,6 +5492,8 @@ void devlink_port_attrs_pci_vf_set(struct devlink_port *devlink_port,
 	attrs->flavour = DEVLINK_PORT_FLAVOUR_PCI_VF;
 	attrs->pci.pf_number = pf_number;
 	attrs->pci.vf_number = vf_number;
+	attrs->pci.multiport = multiport;
+	attrs->pci.subport_number = subport_number;
 	devlink_port_notify(devlink_port, DEVLINK_CMD_PORT_NEW);
 }
 EXPORT_SYMBOL_GPL(devlink_port_attrs_pci_vf_set);
@@ -5508,11 +5523,22 @@ int devlink_port_get_phys_port_name(struct devlink_port *devlink_port,
 		WARN_ON(1);
 		return -EINVAL;
 	case DEVLINK_PORT_FLAVOUR_PCI_PF:
-		n = snprintf(name, len, "pf%u", attrs->pci.pf_number);
+		if (!attrs->pci.multiport)
+			n = snprintf(name, len, "pf%u", attrs->pci.pf_number);
+		else
+			n = snprintf(name, len, "pf%us%u", attrs->pci.pf_number,
+				     attrs->pci.subport_number);
 		break;
 	case DEVLINK_PORT_FLAVOUR_PCI_VF:
-		n = snprintf(name, len, "pf%uvf%u",
-			     attrs->pci.pf_number, attrs->pci.vf_number);
+		if (!attrs->pci.multiport)
+			n = snprintf(name, len, "pf%uvf%u",
+				     attrs->pci.pf_number,
+				     attrs->pci.vf_number);
+		else
+			n = snprintf(name, len, "pf%uvf%us%u",
+				     attrs->pci.pf_number,
+				     attrs->pci.vf_number,
+				     attrs->pci.subport_number);
 		break;
 	}
 
-- 
2.19.2